Why can’t wearing both ear muffs (whether passive or active) and earplugs simultaneously yield more than 36 dB noise reduction ratio (NRR)?

Asked by: Mandi Wadle

Can ear plugs and ear muffs may be used at the same time?

For those who work under extreme noise conditions and do not need to communicate much while working, it is okay to wear both ear plugs and ear muffs at the same time. In doing so, they are ensuring themselves maximum protection from the threat of hearing damage.

Which noise level requires the use of both ear plugs and ear muffs?

100 dBA

Workers exposed to any single impulse noise level that exceed 140 dBA those whose 8-hour TWA exposures exceed 100 dBA should wear double hearing protection (i.e., they should wear earplugs and earmuffs simultaneously).

What is the amount of attenuation achieved when earplugs are worn in combination with earmuffs?

Results: With the muff, plug, and muff and plug in combination, thresholds ranged from 35-48 dB SPL, 40-55 dB SPL, and 44-66 dB SPL, respectively, across the frequencies tested. The combination (without regard to size of plug) resulted in attenuation values of 38-54 dB.

What is the highest noise reduction rating NRR available for ear muffs?


NRR Ratings
The highest NRR rating for earplugs is 33, and the highest available NRR rating for earmuffs is 31. These values reflect the level of noise protection available for each device when worn alone. Combining earplugs with earmuffs can offer a NRR protection level of 36.

What is the difference between earplugs and earmuffs?

Ear muffs will get the job done in most situations, but may cause discomfort in areas with higher temperatures. On the other hand, ear plugs fit directly into the ear canal and offer maximum protection from excessive noise. Their only downside is their size.

Are ear muffs better than ear plugs?

Because they fit directly into the ear canal, ear plugs offer greater protection than ear muffs. This means that ear plugs are suitable when you need the highest levels of protection, for instance in very loud workplaces such as factories, airports, and foundries.

How does dual hearing protection work?

Dual hearing protection involves wearing two forms of hearing protection simultaneously (typically, both earplugs and ear muffs). To estimate the noise exposure for workers wearing dual protection: 1. Determine the employee’s noise exposure without protection in dBA.

How does wearing dual hearing protectors change NRR?

How does wearing dual hearing protectors change NRR? When hearing protectors are worn in combination (i.e. earplugs AND earmuffs), rather than adding the two NRR numbers together, you simply add five more decibels of protection to the device with the higher NRR.

Can you double up hearing protection?

Will doubling up or wearing dual protection-an earmuff in addition to earplugs– provide added protection against extreme noise levels? The answer is yes, according to a recently released Sound Source™ bulletin from the Bacou-Dalloz Hearing Safety Group-but maybe not as much as you thought.

How is double hearing protection NRR calculated?

All it takes is a simple calculation to determine the level your double hearing protection is providing: Add 5 dBA to the highest noise reduction rating of the higher-rated hearing device.

How many dB do earmuffs reduce?

15 to 30 dB

Properly fitted earplugs or muffs reduce noise 15 to 30 dB. The better earplugs and muffs are approximately equal in sound reduction, although earplugs are better for low frequency noise and earmuffs for high frequency noise.

What are passive ear muffs?

Passive ear muffs are made from a wide range of materials and are what most people think of as an ear muff. They block sound using just the foam and other components of the ear cup. In certain industries, such as construction, utilities, and airlines, passive ear muffs have a long history of acceptance.

What is active hearing protection?

Active hearing protection is any type of device that features electrical or digital components that are used to actively suppress or amplify noise from users’ surrounding environments.

What are the functions of earmuffs?

Earmuffs are a type of personal protective equipment (PPE) that is used to protect the wearer’s ears from excessive noise pollution, dust or temperature variations, especially cold.

When should you wear ear muffs?

People should wear a hearing protector if the noise or sound level they are exposed to is close to or greater than the occupational exposure limits (OEL) for noise. For most jurisdictions, this occupational exposure limit is 85 decibels (A-weighted) or dBA.

How many decibels should you wear ear plugs?

Long and or repeated exposure to sounds above 85 decibels can cause hearing loss. The higher the decibel level, the shorter the time it takes for hearing loss to occur. It is recommended that for those sounds above 85 decibels, ear plugs should be worn.

Why shouldn’t you wear hearing protection all the time?

Users may become isolated from their environment, leading to safety risks. This generally may have a tendency to remove the hearing protection and therefore risk damage to their hearing.